Machine for rolling th reads of screws or bolts



(No Model.)

H. A. HARVEY.

MACHINE FOR ROLLING THREADS OF SQREWS 0R BOLTS:

N 25;1,874. g Patented Jan. 3,1882.

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UNITED STATES PATENT Grates.

HAYWARD A. HARVEY, OFORANGE, NEW JERSEY.

MACHINE FOR ROLLING-THREADS 'OF SCREWS OR BOLTS.

SPECIFICATION forming part of Letters Patent No. 251,874, dated January3, 1882.

' Application filed August 22, 1881. (No model.)

To all whom it may concern:

Be it known that I, HAYWARD A. HARVEY,

ofOrange, in the county of Essex and State of New Jersey, have inventeda new Improvement in Machines for Rollin g Threads of Screws or Bolts;and I do hereby declare the following, when taken in connection with theaccompanying drawings and the letters ofreference marked thereon, tobe afull, clear, and exact description of .the same, and which said drawingsconstitute part of this specification, and represent, in-

Figure 1, a front view; Fig. 2, aplan or top "iew; Fig. 3, the diskdetached; Fig. 4:, a section of the die, disk, and fork enlarged. A Myinvention relates to an improvement in machines for threading screws orbolts, particularly to that class in which the thread is produced by thecombined action of a curved stationary die and a cylindrical rotatingdie upon the blank introduced between the said dies and rolled along theface of the stationary die by the friction of the rotating die, thefaces of thetwo dies provided with parallel ribs inclined to the planeof revolution of the rotating die, so thatthe blank rotated between themhas impressed upon its body ascrewthreadfcorresponding to the inclinedribs on the rotating and stationary dies, with special reference to themachine for which Letters Patent ofthe United States were granted to me,dated January 20, 1880, No. 223,730. In

' that patent one part of my invention consisted in combining two ormore pairs of (lies arranged so that the first pair will formcomparatively shallow spiral grooves on the surface of the blank. Thenext pair, to which the,

blank is transferred from the first,will deepen that groove, (and may befinish it or, if other pairs are to be employed, it istransferred fromone pair to the next, each successive pair deepening the groove, untilfinally the last pair of dies completes the thread. l

Mypresent invention relates particularly to mechanism for transferringtheblanks from one pair of diesto the next, and has for its object todispense with the usual checking mechanism-at the feed-channel, and toreceive the blanks directly from the channel into the control of thedevice, which will ultimately transfer the blank from the first pair ofdies to the second, whereby not only the proper presentation of theblank to the first pair of dies is insured, but also its deliveryto thesecond pair of dies after the first shall have performed running closeto the mouth of the feed-chan- 6o nel, and constructed with recesses inits edge, so that the blank at the mouth of the channel rides againstthe periphery of said disk until one of said notches is presented to themouth of the channeh'when the said blank will be forced into said notchby the pressure of the blanks in rear of it, said notch taking it fromits place at the mouth of the channel, and that part of the peripherynext in rear of said recess passing over the mouth of the channel as thesaid recess takes the blank therefrom, and continuing, the second blankfollowing into the second recess, and so on; also, in

forked spring-spindles arranged radially and so as to be revolved in aplane parallel with and concentric. to the revolving die, combined witha cam, stationary or otherwise,which will force the forks successivelyinward as they approach the mouth of the feed-channel, and from whichsaid forks willescape when opposite 'the'"8o mouth of the feed-channel,so as to spring forward and receive within the fork the blank presentedat the mouth of the channel and pass on with the blank, the pressure ofthe spring on the spindle radially outward tending to bear the blankawayfrom the revolving die,

and so that the blank within the fork, as it passes from between thefirst pairof dies,will be pressed radiallytoward the secondpair of diesand away from contact with the first revolving o die into contact withthe second revolving die, thepressure of the spring serving to force thegroove of the blank onto the ribs of the second revolving die, therebyinsuring the proper relation and presentation to the second pair 5 ofdies for the continuation of the work in producing the thread.

The mechanism for making the groove in the blank is substantially thesame as that shown in my patent before referred to. scription of thispart of the machine is therefore all that is required.

A brief (16- too A represents the first curved stationary die, and Bitscorresponding revolving die, arranged upon a vertical shaft, 0; A, thesecond stationary curved die, and B the second revolving die, arrangedupon a vertical shaft, 0, the said two shafts geared together by pinionsD D, power being applied to the shaft 0 through a bevel-pinion (shown inbroken lines, Fig. 1) working into a corresponding bevel-gear, D on theshaft 0. I

E is the feed-channel, arranged in an inclined position to receive acolumn of blanks, the incline being such that gravity alone causes themto gradually slide down the channel, carried by their heads, in awell-known manner for feeding screw-blanks. The revolving and stationarydies have their working surfaces constructed with spiral or inclinedparallel ribs, corresponding to the thread to be produced, so that ablank received from the channel and delivered between the firststationary die, A, and revolving die B will be caused to roll or travelalong the surface of the stationary curved die by the friction oftherevolving die and have impressed upon its surface a groove correspondingto the ribs on the said dies, and arriving by such rotation to the endof the first curved die, a second revolving die takes it and in likemanner rolls it along between its surface and the correspondinglycurveddie and deepens the groove made by the first, and may be finishes thethread.

On the shaft 0 of the first die, or on a hear ing concentric with thatdie, and above it,1 arrange a disk, F, equal in diameter (or nearly so)to the circle of which the revolving die is a segment, so that the edgeof the disk will extend over the space between the revolving andstationary dies. This disk is shown detachedin Fig. 3. In its peripheryare recesses a, equidistant from each other. The extreme depth of thesaid recesses should be substantially the diameter of the blank. Saidrecesses are formed one side nearly radial, the other inclininggradually outward in the direction of the revolution of the disk untilit reaches.

the periphery, as seen in Fig. 3. This disk is arranged so that itsperiphery travels close to the mouth of the feed-channel, and so thatwhen the unbroken part of the periphery of the disk lies in front of themouth of the channel it will hold back the column of blanks in thechannel; but as it passes on and the inclined side of the recess comesbefore the channel the lower blank passes inward on said incline untilit arrives at the full depth of the recess, at which time it is entirelyoutside the channel, and so that, the disk passing on, the said recesswill take the blank from its position at the mouth of the channel andcarry it forward, the periphery of the disk in rear of the blank closingthe mouth of the channel, holding back the second or next blank untilthe next succeeding recess presents itself, when the second blank willbe received in like man- Her, and so continuing, the blanks coming downthe column will be successively taken by each succeeding recess, thecolumn each time checked by the disk which takes away the blank.Rotative movement is imparted to the disk to cause it so to check theblanks by means of a train of gears, G Gr, the driving-gear fast uponthe shaft 0 and the proportion of the gears being relatively such thatthe requisite rotation shall be imparted to the disk, it beingunderstood that the said disk must revolve'only so fast as the blanktravels between the revolving die and the stationary die-that is,aboutone-half the velocity of the revolving die.

To deliver the blanks from'the first pair of dies to the second, Iarrange on the disk F spindles d. These spindles are supported so as tobe freely movable radially toward and from the center of motion of thedisk or die, I

and so as to travel with the'disk-that is, move with the blanks as theytravel between the dies. These spindles are each provided with anindependent sprin 0, the tendency of which is to force them radiallyoutward. Their extreme outward movement is stopped by a collar,f, comingagainst a flange or shoulder. on the disk on which-they are supported.Theouter end of each spindle is made in the shape of afork, h, theopening of the fork corresponding to the blank to be threaded. Theposition of the forks as here represented corresponds to the position ofthe recesses in the disk-that is, the deepest partof the recess, orpoint where the blank comes entirely away from the mouth of the channel,and as seen in Fig. 2. As the spindles revolve they are successivelyforced inward before they arrive in front of the mouth .of the channel.This movement is best made by a stationary cam or incline, n, on thatside of the channel toward which the forks move, so that as the forkscome upon said incline they are gradually forced inward, and so that theextreme outer end of one side will pass the blank. Then the fork,escaping, will be forced by its springoutward and so as to take withinit the blank presented at the mouth of the channel, and continuing itsrotative movement,the fork willcarry the blank supported by its head tothe space between the revolving and stationary dies, and will continueto engage the blank during its travel between the dies, and

so soon as the blank has passed out from between the revolving andcurved diesthe spring upon the fork will force it radially outward,carrying the grooved blank away from the periphery of the revolving dieand against the surface of the next revolving die, the ribs-of that dieentering the grooves i-ntheblank and following on with the blank untilit enters between said-second revolving die and its stationary curveddie. dies, it passes out and away from the fork which delivered it, andthe fork goes on to receive another blank, as before. The forks thusarranged and supporting the blank by the head prevent any axial movementof the blank and Entering between those-- the same relation that itcomes from the first dies, so that the ribs of the second pair of diesare sure to follow the groove made by the ribs of the first dies.

The forked spindles may be used to advantage, in combination with thedisk F, as the checking mechanism for the column. In that case thecheckingadisk will form the support for the spindles; but other checkingmechanism may be employed in combination with the forked spindles, itonly being necessary that there shall be some cheekingmechanism whichwill hold back the column until a fork is presented to receive the blanktherefrom.

The disk may be used without the forks to receive the. blanks from thechannel, as before described. In that case some other transferssuch, forinstance, as that found in my patent before referred tomay be employed.When the forks are used the gearing which imparts a positive rotativemovement to them and to the disk may be dispensed with, because theblanks themselves are forced alongthe circular path by the rotation ofthe revolving die, and they, being within the forks, will necessarilycarry the forks with them, so that the blanks themselves may serve tocarry the forks and the disk to which they are attached; but in thatcase, in starting the machine, and when no blanks are between therevolving and stationary die, it will be necessary to start the forks byhand and carry the first blank into its revolving position between thetwo dies.

If more than two pairs of dies are employed,

like forks may be arranged on the second die,

to successively receive the blanks from the forks of the first pair andin like manner present them to the third pair. In case the forks are notused the disk may be carriedby the blanks in like manner; but in thatcase the recess which receives the blanks must be of such a shape thatthe blank can take a bearingin the recess forward, that is simplya notchin width equal to the diameter of the blank. I claim- 1. In machines forrolling the threads of screws or bolts, a pair of dies consisting of arotating die and a stationary curved die, said dies having ribs on theirworkingfaces for forming the thread of a screw or bolt upon a blankpassing between them, combined with a feed-channel for delivering blanksand a disk arranged above and revolving'in a plane parallel with andconcentric to said revolving dies, the peripheryof said disk runningclose to the mouth of saidchannel, and constructed with recesses tosuccessively receive blanks from said channel and present them to thepassage between said revolving and stationary die, substantiall y asdescribed.

2. In amachine for forming screw-threads, two or more pairs of dies,each pair consisting of a revolving die and a stationary curved die, therespective pairs having ribs on their working-faces, the ribs on the onepair varying in depth or width from those on the other pair, for thepurpose of forming the thread of a screw or bolt by a series of two ormore progressive operations, combined with afeed-channel to present acolumn of blanks to the first pairof dies, and spring-forks arranged totravel in a plane parallel with the revolving die of the first pair andto pass the mouth of said channel, and also arranged to move radiallytoward and from their center of motion, and mechanism, substantiallysuch as described, to force said forks inward as they successivelyapproach the mouth of the feed-channel and embrace the blank presentedat the mouth of thechannel and travel with the blank in its passagebetween the dies, until the blank which they hold, passing from thefirst pair of dies, will be forced from the periphery of the firstrevolving die into contact with the ribbed surface of the secondrevolving die, substantially as described- 3. In a machine for formingscrew-threads, two or more pairs of dies, each pair consisting of arevolving die and a stationary curved die, the respective pairs of dieshaving ribs on their working-faces, the ribs on the one pair varying indepth or width from those on the other pair, for the purpose of formingthe thread of a screw or bolt by a series of two or more progressiveoperations, combined with springforks arranged to travel in a planeparallel with the revolving die of one pair, and also to move radiallytoward and from their center of motion, so that, receiving the blanks,they travel with the same in their passage between the dies until, theblanks which they hold passingfrom the pair of dies which work inconneciion with" said forks, theywill be forced from the periphery ofthe revolving die of that pair into contact with the revolving die ofthe next pair, substantially as described.

H. A. HARVEY. Witnesses:

M. L. ADAMS, E. H. WILLIAMS.

